1. Technical Field
This disclosure relates to disk drives. More particularly, this disclosure relates to edge detection techniques usable in some embodiments to determine the valid track range of one or more disks of a disk drive.
2. Description of the Related Art
During manufacturing of a disk drive, servo sectors are typically written to a disk to define a plurality of evenly-spaced, concentric tracks. Servo writers are typically used to write the servo sectors to the disk during disk drive manufacturing. Servo writers often employ extremely accurate head positioning mechanics, such as laser interferometers or optical encoders, to ensure that the servo sectors are written at the proper radial location, typically, from the inner diameter of the disk to the outer diameter of the disk. In addition, extremely accurate clocking systems may be utilized in order to write the servo sectors in the proper circumferential locations on the disk. Alternatively, instead of utilizing a servo writer, disk drives may perform self servo-writing in which the disk drive itself writes the servo sectors to the disk.
However, due to variability in the manufacturing process, the range of usable disk space between the inner diameter (ID) and the outer diameter (OD) of disk drives can vary.